Though i do not do meds, I did spend time speaking with medicare for my mom and getting her med gap plan for meds chosen. You need to get a Medicare booklet and find out what plans are in your area. Next, layout a table with a calculator to determine what plan or level will fit your needs. There are many Part D options depending on your area. The nice thing is that the medicare representative really helped me figure things out.
A bit of patience and a good calculator are needed. If you are using DMDs, you will know your annual med costs and this helps you choose.